Water-acetone mixtures

Finally, in the last step, the chelating auxiliary had to be removed Ideally, one would like to convert 4.54 into ketone 4.55 via a retro Mannich reaction. Unfortunately, repeated attempts to accomplish this failed. These attempts included refluxing in aqueous ethanol under acidic and basic conditions and refluxing in a 1 1 acetone - water mixture in the presence of excess paraformaldehyde under acidic conditions, in order to trap any liberated diamine. Tliese procedures were repeated under neutral conditions in the presence of copper(II)nitrate, but without success. 

Fig. 41. The pervaporation separation of acetone—water mixtures achieved with a water-selective poly(vinyl alcohol) (PVA) membrane and with an acetone-selective siUcone mbber membrane. The PVA membrane is best suited to removing small amounts of water from a concentrated acetone solution, whereas the siUcone mbber membrane is best suited to removing small amounts of acetone from a dilute acetone stream (89).

A mixture consisting of 22.7 g potassium o-bromobenzoate, 16.6 g 2,6-dichloro-3-methvlani-line, 12 ml N-ethylmorpholine, 60 ml diethylene glycol dimethyl ether, and 1.0 g anhydrous cupric bromide is heated in a nitrogen atmosphere at 145 C to 155°C for 2 hours. The reaction mixture is diluted with 60 ml diethylene glycol dimethyl ether and acidified with 25 ml concentrated hydrochloric acid. The acidic mixture is diluted with 100 ml of water and the liquid phase decanted from the insoluble oil. The insoluble oil is stirred with methanol and the crystalline N-(2,6-dichloro-3-methylphenyl)anthranilic acid which separates is collected and washed with methanol. The product, after recrystallization from acetone-water mixture melts at 248 C to 250°C. 

Metwally et al. [28] also studied the resin-catalyzed hydrolysis of ethyl formate in acetone-water mixtures at different temperatures. The experimental results indicated a linear dependence of the logarithm of rate constant on the reciprocal of the dielectric constant (Fig. 2). The decrease of dielectric constant may lower the concentration of the highly polar transition state and thereby decrease the rate [28]. 

Company, Inc.) was recrystallized from an acetone-water mixture to give the pure acid, m.p. 162-163°. 

Solubility of Pentaerythritol Tetranitrate in Acetone-Water Mixtures [Aubertein (Ref 11)]... 

A process for the production of cellulose acetate fiber produces a waste stream containing mainly air but with a small quantity of acetone vapor. The flowrate of air is 300 kmol h-1 and that of acetone is 4.5 kmolh-1. It is proposed to recover the acetone from the air by absorption into water followed by distillation of the acetone-water mixture. The absorber requires a flow of water 2.8 times that of the air. 

Dehydrate through acetone-water mixtures and pure acetone. 

Scheme 2 shows preparation of the biftinctional fiber. PPPE-c and PPPE-f grafted with CMS and ST were functionalized by the reported method.6 Here, an example of functionalization procedures is described. The precursory fibers (PPPE-f grafted with CMS and ST, 2 g) and triethyl phosphite (60 ml) were taken into a three-necked flask (200 ml) equipped with a Liebig condenser. After the mixture in the flask was heated for 48 h at 100 °C, the resulting phosphorylated PPPE-f was washed with acetone, aceton-water mixture and water, and dried in vacuum oven at 40 °C. In order to introduce sulfonic acid groups, the phosphorylated PPPE-f was treated with a 30 mL of 1,2-dichloroethane solution of chlorosulfonic acid (10 wt %) for 2 h at room temperature. Finally, diethyl phosphonate groups on the fibers were hydrolyzed with 12 M hydrochloric acid under refluxed... 

Solubilities of LaCl3-7H20 and of NdCl3-6H20 in acetone/water mixtures have been reported, and compared with those for chlorides of barium and of the alkali metals (323). For these trichlorides, the solubility increases as acetone is added to water up to about 15% acetone, then decreases (LaCl3 and NdCl3 are effectively insoluble in acetone itself). There is also some information, presented only in graphical form, on solubilities of praseodymium trichloride in water-rich methanol, ethanol, and ether mixtures (314), and one fact on yttrium trichloride in a water/ether mixture (264). 

A full report has now appeared of solvent effects on the rates of hydrolysis of benzyltriphenylphosphonium bromide. The remarkable increase in rate in media of low polarity is largely attributable to a shift of the pre-equilibrium between phos-phonium and hydroxide ions in favour of the intermediate hydroxyphosphorane.129 In a similar vein, a study of medium and deuterium isotope effects on the rate of hydrolysis of tetraphenylphosphonium chloride in acetone-water mixtures has been reported.130... 

Parker and Eberson [17] demonstrated that the oxidation of 9,10-dibromoanthracene in the presence of a nucleophile (e.g. 3,5-lutidine) results in the replacement of a bromine by the nucleophile. In a series of papers [18], various polyfluoroaromatic amines were oxidized at platinum in an acetone-water mixture for example, octafluoroacridone was synthesized from 2-aminononafluorobenzophenone (Scheme 2). 

To 10.3 g, 0.075 mol aminobenzoic acid neutralized with 5 mol/L sodium hydroxide (or to 3-acetyl aniline in 250 mL of water), was added sodium chloroacetate (26.2 g, 0.225 mol). The solution was refluxed, and the pH was maintained between 10 and 12 by the addition of 5 M aqueous sodium hydroxide solution. After the pH ceased to fall, the solution was refluxed for an additional 1 h and then cooled and acidified with 0.5 mol/L HCl. The crystals were vacuum filtered and dried under high vacuum. The product was recrystallized from an acetone/water mixture. The yield of these aryliminodiacetic acids reaction varied from 3.1 g to 5.3 g. 

These derivatives are soluble in an acetone/water mixture with their p i values similar to that of PIDAA. The phenylene analogs are similar to EDTA except that the two nitrogens are bridged by aromatic rings. These derivatives are soluble in acetone/water. They were characterized by measuring their H- and C-nuclear magnetic resonance (NMR) spectra and Fourier transform infrared (FTTR) spectra. All the PIDAA derivatives showed a peak near 53 ppm for the methylene carbons in carbon NMR spectra. The methylene carbon resonance appears around 44 ppm in the NPG derivative. Thus offers an easier way to characterize these materials. The FTNMR data are listed in Table 1 below. 

These reactions are often conducted in water, or in acetone-water mixtures for higher molecular weight amines.Magnesium sulfate is frequently used as an additive in these reactions to control solution pH. 1,3,5,7-Tetranitroadamantane (71) has been obtained via the permanganate oxidation of the hydrochloride salt of 1,3,5,7-tetraaminoadamantane (70) (Table 1.7). The 45 % yield for this reaction reflects a relative yield of 82 % for the oxidation of each of the four amino groups. 

Mixtures of organic solvent and water have also been studied (Scheme 11). hi this context, Watanabe and coworkers studied the catalytic dehydration of fructose to HMF at 150°C in acetone-water mixtures and in the presence of a cation-exchange resin catalyst (Dowex 50wx8-100) [92]. The use of acetone-water (70 30 w/w) as reaction medium resulted in a yield of HMF of 73% at 94% conversion. Moreover, under these conditions, the catalyst was stable for at least five catalytic runs. Assistance of microwave not only increased the selectivity to HMF but also had a beneficial effect on the reaction rate. In this context, Gaset et al. studied the activity of Lewatit SPC-108 (cation-exchange resin) in a mixture of organic solvent (MIBK or diethyl ketone or benzonitrile or butyronitrile or dichlor-oethylether or nitropropane) and water (from 1/7 to 1/12 by volume) at a temperature around 85-90°C Under these conditions, HMF has been obtained with a yield of 70-80% [93, 94]. 

When crystallized from an acetone-water mixture, benzoic acid is obtained as the crystalline needles shown in Figure 1 A. On the other hand, a mixture of needles and irregular crystalline solid is obtained from methanol-water mixtures (Figure IB). From pure water, aggregates of monoclinic crystals are obtained (Figure 1C). 

Water-soluble catalysts for Oppenauer-type oxidation of alcohols can be achieved by adding functionalized salts of classical ligands such as dipotassium 2,2 -biquinoline-4,4 -dicarboxylate (BQC) to acetone-water mixtures. In this way, the catalyst system [ Ir(ix-Cl)(cod) 2]/BQC is highly efficient for the selective oxidation of a wide range of alcohols such as benzylic. 

Osmylation of the olefmic ester 151 in an acetone-water mixture proceeds with high diastereoselectivity to produce the lactone 152 in a one-pot procedure (Equation 52) <1999TL5791>. 

C for up to 4 h to complete conversion into tra i-PtCl2 (CH3)2C=NOH 2. The process of cis-trans isomerization can be monitored by TLC. The yield of fra 5-PtCl2 (CH3)2C=NOH 2 is almost quantitative. The beige product can be recrystallized from a boiling acetone/water mixture (3 4 in v/v, 1 g in 35 mL) to give pale yellow crystals. 

The nitrosation of 2,5-diphenylpyrrolidine in an ice-cold solution of ethanol and hydrochloric acid with sodium nitrite produced the expected iV-nitroso-2,5-diphenylpyrrolidine. The product could be separated into trans and cis isomers by fractional crystallization using acetone-water mixtures. The ratio of trans to cis isomer was found to be 2.5 1. When the nitrosation was carried out in an acetic acid solution, the ratio of trans to cis isomer remained the same although the yield of the identified products was somewhat lower (71 vs 56 %) [29]. The ratio of the isomers of the starting pyrrolidine was not reported. 

These days everybody is talking about ginkgo biloba, a concentrate made from the extracts of the leaves of a tree that has been around for over two hundred million years. The species was brought from China to Europe in the eighteenth century, and it became a popular decorative tree. It also serves a medicinal purpose. The leaves are picked, dried, and ground to a powder. This powder is extracted with an acetone-water mixture, and then these solvents are evaporated off. The residue that remains is compacted into a variety of pills. Several components of this residue may have beneficial effects in particular, they may improve circulation to the brain. Clinical studies have confirmed that ginkgo extracts dilate blood vessels and improve blood flow in arteries and capillaries. Two classes of... 

The preparation, composition, structure and leaching characteristics of a crystalline, ceramic radioactive waste form have been discussed, and where applicable, compared with vitrified waste forms. The inorganic ion exchange materials used such as sodium titanate were prepared from the corresponding metal alkoxide. The alkoxides were reacted in methanol with a base containing the desired exchangeable cation and the final powder form was produced by hydrolysis in an acetone-water mixture followed by vacuum drying the precipitate at ambient temperature. 

Figure 19. PMR spectra at 185°K for magnesium perchlorate in acetone-water mixtures at low water content (6) showing mixed solvate species.

In 1953 Olson and Konecny (19) studied the conductance of lithium bromide in acetone-water mixtures at 25°C and 35°C. They calculated KD and Ao in the acetone-rich solvents by the Fuoss method and Ao in the water-rich solvents by extrapolation of the phoreogram. They found that as the water content increases Kd increases, Ao decreases but then undergoes an increase, and a increases from slightly less than the sum of the crystal ionic radii to the sum of the radii of the fully hydrated ions. Extrapolation of their data for A0 to zero water content is not reliable because of the large concave upward negative slope however, it would appear to lead to a value of about 220 U l cm2 eq-1. Similar extrapolations of values for Kd and a yield 2.0 X 10 4 and 2.2 A, respectively. 

A more recent study using dry acetone and acetone-water mixtures was reported by Nilsson and Beronius (22). For acetone containing 0.005% by weight they found Ao, KA, and a to be 195.0 fi-1 cm2 eq-1, 4202, and 9.3 A, respectively. All three of these parameters were found to decrease as the concentration of water was increased. They suggest that the change in these parameters is a result of the strong solvation of the salt by the water. Nilsson (23) conducted similar studies on acetone and methanol mixtures and noted similar results. 

Our reported pKs values in ethanol-water and in acetone-water mixtures at 25°C are in fair agreement with previously reported values (18,31). Deviations are less than 0.08 in all cases where there is more than 50% water present. 

A partially hydrolyzed acrylamide gel underwent a phase transition in acetone/ water mixtures [21]. The main polymer-polymer affinity is due to the van der... 

Before the phase transition was found, a shrinking and swelling effect of an electric field was recognized and studied by several researchers [40-43]. Tanaka and colleagues found the phase transition in hydrolyzed acrylamide gel in 50% acetone/water mixtures. Their original interpretation that the electrophoresis of the polymer network might be responsible for the phase transition does not seem correct [44]. The most important effect seems to be the migration and redistribution of counter and added ions within the gel [45]. 

Due to this shift, the experimentally determined extent of the collapse Ae is smaller than the one determined by Maxwell s construction. Also the value Xc found by employing Maxwell s construction is somewhat higher than the respective y of the acetone-water mixture at which the collapse takes place and which have been determined for the uncharged PAAm network. 

Fig. 13. Dependence of the swelling ratio X and modulus G (gem 2) on the acetone content a (vol %) in acetone-water mixtures for polyacrylamide networks A,B,C, D, E and F with 0.02,0.1, 0.115,0.2 and 0.7 gofMBAAm (the amount ofAAm was 7 gin 100 ml solution) (O) X, ( ) G. From Ilavsky and Hrouz [26]...

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